Q500 analyzer

The composites' morphologies were characterized by scanning electron microscopy (SEM) using a JSM6510 microscope (JEOL) using the secondary electron mode. Thermal analysis was conducted at the range of 25 °C to 600 °C using a Q500 analyzer (TA Instruments, New Castle, DE, USA) with a heating rate of 10 °C min⁻¹ under nitrogen atmosphere. For the differential scanning calorimetry (DSC), samples were heated from 25 to 250 °C in a DSC Q100 (TA Instruments, USA) under nitrogen atmosphere. Fourier Transform Infrared was carried out in an FTIR spectrophotometer VERTEX 70 (Bruker Corporation) with ATR technique. Proton and carbon nuclear magnetic resonance (¹H- and ¹³C- NMR) spectra were obtained on a 600 MHz Avance III HD Bruker spectrometer using dimethyl sulfoxide (DMSO-d₆) as a solvent and tetramethylsilane (TMS) as the internal reference.

The
mechanical properties of samples were characterized by uniaxial tensile
tests on a dual column Instron 3365 universal testing machine equipped
with a 500 N load cell. The tensile measurements were conducted according
to ASTM D 882 Standard Test Methods for Tensile Properties of Thin
Plastic Sheeting. For this, dog-bone shaped samples (25 mm length,
4 mm width) were stretched at a rate of 2 mm/min. Stress–strain
curves were recorded at 25 °C and 44% relative humidity (RH).
A minimum of seven measurements was carried out for each sample, and
the results were averaged to obtain a mean value. The values of Young’s
modulus, toughness (taken as the area below the curve, i.e., the fracture
energy), stress, and elongation at break were calculated from the
stress–strain curves.
The thermal degradation behavior
of lignin-based bioplastic samples was investigated through thermogravimetric
analysis (TGA) using a Q500 analyzer from TA Instruments. The measurements
were carried out under an inert N₂ atmosphere on 3 mg samples
in an aluminum pan at a heating rate of 10 °C/min, from 30 to
600 °C. The weight loss (TG curve) and its first derivative (DTG
curve) were recorded simultaneously as a function of time and temperature.

SEM and EDS analyses were performed on a JSM-IT500HR scanning electron microscope (JEOL, Tokyo, Japan) equipped with an Xplore EDS detector (Oxford Instruments, Abingdon, UK) with acceleration voltages ranging from 5 to 10 kV. The materials were coated with platinum prior to SEM observation. PXRD patterns were obtained using a SmartLab diffractometer (Rigaku, Tokyo, Japan). ATR-FTIR spectra were acquired using a Nicolet iS50 spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). TGA measurements were performed using a Q500 analyzer (TA Instruments, New Castle, PA, USA) by heating the sample from 30 to 800 °C at a rate of 10 °C/min under nitrogen gas. DVS measurements were performed at 25 °C using a DVS Intrinsic analyzer (Surface Measurement Systems, London, UK). Nitrogen adsorption measurements were performed at 77 K using an ASAP 2020 system (Micromeritics Instrument Corp., Norcross, GA, USA). Before analysis, the samples were degassed at 393 K for 2 h under vacuum. The nitrogen isotherm data were used to calculate the specific surface area using the BET method and the pore size distribution using a DFT model.

The fiber morphology was observed using a Leica Cambridge Stereoscan 360 Scanning Electron Microscope (SEM) operating at 20 kV. The samples were sputter-coated with gold prior to examination.
The fiber diameter distribution of each scaffold was determined by measuring 100 fibers, and the results are given as the average diameter ± standard deviation.
The encapsulation efficiency (EE) was calculated by the following equation: $EE (\%)=\frac{Actual drug amount}{Theoretical drug amount}\times 100$
where the $Actual drug amount$ was determined by the assay methods reported in Section 2.2.3 andSection 2.2.4.
Thermogravimetric analyses (TGA) were carried out using a TA Instruments (New Castle, DE, USA) Q500 Analyzer. Samples were heated at a rate of 10 °C min⁻¹ from RT to 700 °C, under nitrogen flow. Differential scanning calorimetry (DSC) was carried out with a TA Instruments DSC Q2000 equipped with a refrigerated cooling system (RCS). The samples were subjected to a first heating scan at 20 °C min⁻¹ from −90 °C to 200 °C, followed by quenching, and a second heating scan at 20 °C min⁻¹.